Just as described, I can provide power into the drone via the USB cable, and it will do the breathing blue LED startup sequence, then it will give a quickly flashing red LED and a tone (GPS Failed tone). Then, when I try to do the setup outside, with the GPS connection, I get a purple light quickly flashing and the low battery tone, which, once plugged in, is replaced by the first, quick red flashing LED with the same low battery tone. The battery is definitely charged, as I left it plugged in all weekend.
I’m used to not having to have GPS or battery plugged in for any kind of connection to occur, and I cannot even connect now. I’ve already tried to download the latest version of QGroundControl, as well as their stable build, and the latest Mission Planner.